1. Field of the Invention
The present invention relates to a fastening device in an IC socket, especially and more particularly to an improved fastening device which retains the IC socket in a tight status thus securing an IC therein.
2. Description of the Prior Art
Some ICs such as central processing units (CPUs) are quite sensitive to temperature, thus they are apt to be damaged if exposed to high temperature for a period of time such as being directly soldered onto a printed circuit board. Therefore, it is common to provide an IC socket mating with the pins of the IC to replace the latter to be directly soldered on the printed circuit board, thus preventing the IC from being directly exposed to high temperature. For this purpose, a conventional IC socket is provided as shown in FIG. 6. The conventional IC socket shown separately comprises a base 90, a cover 80 slidably engaged on the base 90, and a crank 9 received in between the cover 80 and the base 90. The cover 80 defines a plurality of holes 81 in rows therein. Two ears 82 are formed on one side of the cover 80. The base 90 defines a plurality of slots 91 each of which corresponds to a hole 81 of the cover 80 and remains in communication with the hole 81 when the cover 80 slides on the base 90. The crank 9 comprises a lateral portion 94 and a longitudinal portion 95 perpendicular to the later portion 94. The lateral portion 94 of the crank 9 includes a substantially U-shaped portion 940 at a middle portion thereof and two straight portions 941 extend from the U-shaped portion 940. The U-shaped portion 940 has two pitches 942 at two sides thereof. The lateral portion 94 of the crank 9 is received in between the cover 80 and the base 90 while the longitudinal portion 95 thereof is exposed out of the cover 80 and the base 90. Normally the IC socket is defined as in a tight status where the longitudinal portion 95 is substantially adjacent to the side where the two ears 82 formed and a portion near one end of the longitudinal portion 95 is retained in between the two ears 82. In the tight status, each pair of the hole 81 and the slot 91 firmly receives an IC pin (not shown) of an IC (not shown), therefore the IC pin is not easily pulled out from the IC socket. When a user lifts the longitudinal portion 95 of the crank 9, the cover 80 is slid forward by the crank 9 for a distance less than a width of the slot 91, thus releasing retention on the IC pin and allowing the user to pull the IC from the IC socket easily. However, the conventional IC socket may be accidentally loosened from its tight status due to transportation shaking or accidental touch on the longitudinal portion 95 of the crank 9. FIG. 7 illustrates a portion of the longitudinal portion 95 of the crank 9 is retained in between the two ears 82. Since only one third of the periphery of the longitudinal portion 95 is in contact with the ears 82, the retention on the longitudinal portion 95 of the crank 9 is apt to be removed by accidental touching or vibration.
It is requisite to provide a new fastening device which retains the IC socket in tight status regardless accidental touch or shaking.